title: Using proton transfer reaction mass spectrometry for online analysis of secondary organic aerosols.
abstract: Proton-transfer-reaction mass spectrometry (PTR-MS) is a useful tool in ambient trace gas analysis, especially for the analysis of oxygenated volatile organic compounds (OVOC). Many OVOCs are produced during photooxidation of volatile organic compounds and contribute to both the gas phase and secondary organic aerosols (SOA). The inlet system of the PTR-MS instrument was modified to allow also for the measurement of the particulate phase of an aerosol with a high time resolution. The new inlet consists mainly of a denuder to strip off the gas phase, and a heater (120/150 degrees C) to vaporize the aerosol particles. This inlet system was tested with pinonic acid particles generated with a nebulizer and SOA particles formed during the photooxidation of 1,3,5-trimethylbenzene and alpha-pinene with NO(x) in a smog chamber. The performance of this new technique is discussed and the partitioning coefficients for the oxidation products are estimated.
authors.affiliation: Laboratory of Atmospheric Chemistry, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. heidi.hellen@fmi.fi
authors.forename: Heidi
authors.initials: H
authors.lastname: Hellén
authors.forename: Josef
authors.initials: J
authors.lastname: Dommen
authors.forename: Axel
authors.initials: A
authors.lastname: Metzger
authors.forename: Astrid
authors.initials: A
authors.lastname: Gascho
authors.forename: Jonathan
authors.initials: J
authors.lastname: Duplissy
authors.forename: Torsten
authors.initials: T
authors.lastname: Tritscher
authors.forename: Andre S H
authors.initials: AS
authors.lastname: Prevot
authors.forename: Urs
authors.initials: U
authors.lastname: Baltensperger
mesh_terms: D000336:Aerosols / Q000032:analysis* / Q000737:chemistry; D000081008:Bicyclic Monoterpenes; D013058:Mass Spectrometry / Q000379:methods*; D008970:Molecular Weight; D039821:Monoterpenes / Q000032:analysis; D009862:Online Systems; D009930:Organic Chemicals / Q000032:analysis*; D010316:Particle Size; D011522:Protons; D012905:Smog / Q000032:analysis; D013997:Time Factors
chemical_list: D000336:Aerosols; D000081008:Bicyclic Monoterpenes; D039821:Monoterpenes; D009930:Organic Chemicals; D011522:Protons; D012905:Smog; C005451:alpha-pinene